In a large skillet, cook bacon over medium heat until crispy and golden. Drain bacon on paper towels, Reserve 3 tbsp. fat. In the same skillet, heat bacon fat and canola oil. Add onions and cook covered, over low heat for 10 minutes. Uncover pan and continue to cook, stirring occasionally, until onions are very soft, 10–15 more minutes. Stir in bacon, white wine vinegar, thyme, and salt and pepper to taste.